Folate dosage and evidence
Written by Aaron CuhaReviewed Sep 2026
The short answer
B vitamins reliably lower homocysteine, an amino acid in the blood linked to heart disease. Two big trials, HOPE-2 and NORVIT, then showed that lowering it did not prevent heart attacks or strokes. An MTHFR gene result is background, not a plan. Check B12 before you add folate.
Evidence grade for Folate: Preliminary. The rule: studied in people, but no published study has had people take it. The sum on this page: 2 human studies where nobody was given it. A grade counts how much has been done to people, not whether it works.
- People given it
- 0
- Human studies
- 0
- Found nothing
- 0
Dose
No human dose established
No published study on this page has given this compound to people and reported a result.
2 human studies where nobody was given it
2 effects reported, 2 unwanted, by people using it, not a trial
Goal pages: Heart and circulation
In plain English
In plain English, from Aaron
This is how I would explain it to a friend. The evidence, with the numbers, is further down the page.
Folate is a B vitamin. It is also sold as folic acid or methylfolate. With B12, it lowers homocysteine, a blood marker tied to heart disease. It does lower that number. The problem is that lowering it did not protect people's hearts.
What people take it for
- Lowering high homocysteine.
- Protecting the heart and blood vessels.
- Because a gene test showed an MTHFR variant.
What studies in people showed
Two big trials came out the same week. In HOPE-2, people with heart and blood vessel disease took folic acid, B6 and B12. Their homocysteine went down. Their deaths, heart attacks and strokes did not. In NORVIT, people who had just had a heart attack got the same result, and there was a worry about harm. Pregnancy is a different story. There, folate helps prevent birth defects, and that belongs with your doctor.
What people report
Reports, not study results
The good
- We have not collected user reports on this one yet.
The bad
- The risk this page flags: taking folate before checking B12 can hide a B12 shortage while nerve damage keeps going.
- In the NORVIT trial, B vitamins after a heart attack raised a worry about harm.
Where these come from: We have no forum or clinic reports for this one. The risks listed come from the trials and warnings on this page.
My bottom line
Test first. Check homocysteine and B12 before you take folate, because folate can hide a B12 problem. And do not take it to protect your heart. The big trials say it did not.
An opinion, not a finding. I am a coach, not a doctor.
What it has been measured to do
Measured in people
Goals Folate has been tested for in people, biggest studies first. We count only what the studies on this page say, so the real numbers may be higher.
- Heart attacks and strokesno headcount stated · 2 studies · 2 found nothing
35 of the 36 indexed goals have no study of any kind behind Folate
No study in people, animals or cells on this page reports a result for these. That does not prove Folate does nothing for them. It does mean anything you have heard about Folate and one of these did not come from a study cited here.
When this earns a spot
It earns a spot when homocysteine is high and B12 has been checked. The MTHFR gene is background. It does not earn a spot because lowering homocysteine sounded like it should prevent heart attacks. The HOPE-2 and NORVIT studies moved the number, not the heart attacks and strokes.
Aaron's list, tier 2
Bloodwork that belongs beside the bottle
Always test B12 and MMA too when the question is a high homocysteine.
Test again after about 90 days. If that blood number did not move, stop.
- Taking folate first can hide a B12 shortage.
- A normal folate blood level does not mean your body is using it well.
Reading the number
If homocysteine did not move, stop. If it moved, do not celebrate a health benefit the large studies did not show.
What these tests mean: Homocysteine.
What people typically order
Ask for homocysteine, B12, MMA and folate. /bloodwork/partners is where to get the blood drawn.
Show full evidence
What is Folate?
B vitamins reliably lower homocysteine, an amino acid in the blood linked to heart disease. Two big trials, HOPE-2 and NORVIT, then showed that lowering it did not prevent heart attacks or strokes. An MTHFR gene result is background, not a plan. Check B12 before you add folate.
Folate is the B vitamin in Aaron's methylated-B rule, used against high homocysteine. The chemistry works. At the scale that matters, the results in people do not.
HOPE-2 gave people with heart and blood vessel disease folic acid plus B6 plus B12, and it lowered their homocysteine. It did not cut the main thing it measured: deaths, heart attacks and strokes. NORVIT, in people who had just had a heart attack, also lowered homocysteine and did not prevent more heart problems. Those two papers are why this page will not sell you a methylated B stack as heart medicine.
Preventing birth defects of the spine and brain in pregnancy is a different, proven use. That belongs to prenatal care, not this page. The practical harm this page exists to prevent is this: taking folate first can hide a B12 shortage.
How does Folate work?
Folate hands off small carbon pieces the body uses to build and repair. Together with B12, it turns homocysteine back into methionine. 5-MTHF is the ready-to-use form, sold to people who know their MTHFR gene type. The gene type changes how fast the enzyme works. It does not, on its own, tell you a dose.
What have studies in people found about Folate?
The number moves. The big heart trials did not deliver the benefit the homocysteine story promised.
- HOPE-2: homocysteine went down, but deaths, heart attacks and strokes did not.
- NORVIT: the same pattern after a heart attack, plus a worry about harm.
- Preventing spine and brain birth defects in pregnancy is a separate use that belongs with your doctor. It is not what this page is about.
What this does not tell you: These trials do not say folate is useless in a real shortage or in pregnancy. They say that lowering homocysteine in people with heart disease did not protect their hearts. Check B12 and MMA (methylmalonic acid, a B12 marker) before you add folate for high homocysteine.
The evidence, in charts
Fig. 1a · how many people
2studies in people cited, but none says how many people took part
number of people not stated
We do not draw a total, because none of the studies in people on this page gives one. Read the sources below for what each study measured.
We read the number of people from the source lines on this page. Where a line gives no number, we count nothing for it. We do not guess.
Fig. 1b · evidence mix
All 2 sources here are studies in people.
- Study in people · done in people2100%
Counted from the list of sources on this page. It counts only what we cite, so there may be more studies out there. A review counts once, however many studies it sums up.
Fig. 2 · evidence over time
Every source here was published in 2006.
Too few different years on this page to draw a timeline. The newest source on file is from 2006, more than five years ago. Research on it may have gone quiet.
Fig. 3 · legal status at a glance
US
Not approved
UK
Not approved
AU
Not approved
CA
Not approved
Not approved in any of the four countries shown. This is what the law says, not a verdict on the science. See Legal status below for the full text and any notes.
Fig. 4 · how much does what
Nobody has tested different amounts in people
This chart would show how the effect changes as the amount goes up. For this compound, nobody has measured that in people. So we leave it empty. We will not borrow an animal chart and pretend it works the same in people.
Fig. 5 · what the molecule is
- Kind of compound
- Supplement
- Molecule weight
- Not on file
- Half-life
- None on file
- Chain length
- None on file
No amino acid sequence is on file for Folate, which is expected: a supplement is not built from amino acids.
The studies we cite
- Study in people2006Homocysteine lowering with folic acid and B vitamins in vascular disease.
Lowering homocysteine did not protect the heart. People with heart and blood vessel disease took folic acid, B6 and B12, and their homocysteine dropped. Deaths, heart attacks and strokes did not.
HOPE-2. Folic acid plus B6 plus B12 lowered homocysteine. The primary composite of death, myocardial infarction, and stroke did not improve.
- Study in people2006Homocysteine lowering and cardiovascular events after acute myocardial infarction.
The same result in people who had just had a heart attack. B vitamins lowered homocysteine but did not cut further heart problems, and they raised a worry about harm.
NORVIT. After myocardial infarction, B-vitamin homocysteine lowering did not reduce events and raised concern about harm. Same week as HOPE-2.
Common questions
Has Folate been tested in people?
Not in a completed trial cited here. 2 human studies where nobody was given it. B vitamins reliably lower homocysteine, an amino acid in the blood linked to heart disease. Two big trials, HOPE-2 and NORVIT, then showed that lowering it did not prevent heart attacks or strokes. An MTHFR gene result is background, not a plan. Check B12 before you add folate.
What is the Folate dosage?
No human dose established. No published study on this page has given this compound to people and reported a result. 2 human studies where nobody was given it
Is Folate FDA-approved?
Sold as a supplement. Folic acid is also in licensed medicines for pregnancy and for low folate. Not approved to prevent heart attacks by lowering homocysteine.
I have an MTHFR variant. Do I need methylfolate?
It is background. Aaron's rule still waits on your homocysteine result, and still wants B12 checked. A gene variant is not a standing order.
Can I start folate today and test later?
Not if B12 has never been checked. Folate can fix the blood count signs of a B12 shortage while the nerve damage keeps going.